Viaducts are structures that are designed to carry large amounts of traffic over a short distance. They are usually built over a river or a canal.
To disembark is to leave a ship, train, or airplane. Sometimes passengers will have to disembark at a separate location, such as a port.
A turtleneck is a type of clothing that is made from a tight-fitting fabric that is usually worn over a shirt. The turtleneck is often considered to be a masculine garment, because it is usually worn by men.
When something reemerges, it comes back to the surface. This might mean that the thing is coming back to life, or it might mean that the thing is becoming more common again.
When someone is retreating, they are moving away from something. They might be retreating from a fight, or they might be retreating from the competition.
To reinvent something is to create a new version of it. When you reinvent a product, you create a new version that is different from the original.
To default on a debt is to not pay it back. When a company or government defaults on a loan, they are not following through with their promise to pay back the money that they borrowed.